1. Field of the Invention
The present invention relates to a photosensitive material scan-exposure method and a photosensitive material exposure apparatus, and is applicable to, for example, a photographic printer.
2. Description of the Related Art
An exposure apparatus in which images are printed onto a photosensitive material such as a photographic printing paper includes, for example, an exposure apparatus in which exposure is effected by main scanning and sub-scanning.
In this exposure apparatus, exposure is carried out while a plurality of rows of photosensitive materials are conveyed. Main scanning is effected by a print head in which optical shutters are arranged in one dimension, i.e., the column direction and the vertical direction of a photosensitive material. Sub-scanning is effected in the conveying direction of the photosensitive material.
For example, in a case in which two rows of photosensitive materials are subjected to scan-exposure, the direction which runs along the column direction is the sub-scanning direction and the direction which is orthogonal to the sub-scanning direction is the main scanning direction. Accordingly, locus 100 of scanning beams is illustrated as shown in FIG. 4B. An area (W.times.L) which is surrounded by a dashed line in FIG. 4B denotes an image forming area 102. In FIG. 4B, a part of the locus 100 is unillustrated.
In the exposure apparatus, it is efficient to expose a plurality of photographic printing papers P. However, there are following drawbacks: (a) since a plurality of images are disposed in a row in the main scanning direction, it is necessary to rearrange the image data before exposure (e.g., in a case in which there are two images A and B, the information on the image A and the information on the image B are read for every one line of the main scanning and the image information is handled alternately (A, B, A, B . . . ); (b) since the sub-scanning direction is generally longer than the main scanning direction (the length of a photographic printing paper P in the transverse direction is generally longer), the response time of a linear image display element such as an LCD is slow and it is difficult to decrease the exposure time; (c) the time in which the single row is subjected to exposure is the same as the time in which a plurality of rows are subjected to exposure (as shown in FIG. 5B, even if the photographic printing paper P is disposed at only one row, a plurality of rows are subjected to main scanning. Consequently, it is a waste of time that the rows without photographic printing paper P are subjected to main scanning.).